Frank Low, 1933-2009: Trailblazer for infrared astronomy

June 28, 2009|By Thomas H. Maugh II, Tribune Newspapers

Astronomer Frank Low, the experimental genius who developed and distributed sensors for infrared astronomy and performed the first successful observations above the Earth's atmosphere, died Thursday, June 11, in Tucson, Ariz., after a long illness, the University of Arizona announced. He was 75.

One of the fathers of infrared astronomy, Mr. Low "basically unlocked problems such as how stars form, led to the first observations of light from extrasolar planets, and totally revolutionized our view of the energetics and evolution of galaxies," said Jet Propulsion Laboratory astronomer Michael Werner, project scientist on NASA's Spitzer Space Telescope.

Mr. Low "not only had tremendous technical insight that resulted in huge leaps [in astronomy], but he also founded a company where he sold the very latest astronomical equipment he could figure out how to build," added astronomer George Rieke, a longtime colleague at the University of Arizona. "Sometimes he gave it away."

Working at Texas Instruments in 1961, Mr. Low developed a gallium-doped semiconductor that could measure very low temperatures by changes in its electrical resistance. He recognized that the thermometer could also serve as a sensitive detector, or bolometer, for an infrared telescope at wavelengths that were too short to be detected with existing telescopes. All objects in the universe emit heat, and he reasoned that an infrared detector could reveal many celestial objects.

He took a prototype bolometer to the National Radio Astronomy Laboratory in Green Bank, W.Va., in 1962 and demonstrated it successfully. But there was a problem. Infrared or IR radiation is absorbed by water vapor in the atmosphere, so very little of it actually reaches ground-based detectors. Using a ground-based observatory, Mr. Low and graduate student Doug Kleinmann discovered what is now known as the Kleinmann-Low Nebula, which is the prototype for regions of very early star formation.

To escape as much of the atmospheric water vapor as possible, Mr. Low built a 12-inch telescope with an IR detector that in 1969 was mounted in a Learjet operated by NASA.

Using this instrument, Mr. Low observed, among other things, that Jupiter and Saturn emitted more heat than they absorbed from sunlight, indicating the presence of some sort of internal energy source.

But it was clear that really good observing would require a telescope totally above the atmosphere -- that is, in space. Mr. Low proposed the Infrared Astronomy Satellite, or IRAS, and, with Gerry Neugebauer, James Houck and Fred Gillett was a prime mover in designing it and getting it launched in 1983.

IRAS, a wide-angle telescope, surveyed the entire sky in the middle- and long-wavelength IR regimes, and its data are still being mined 26 years later.